Aeroplane control



Sept.2,' 1930. o'. A. scHAER AEROPLANE CQNTROL Filed July l1, 1929 iMesh/697: 0. d?. Schwer,

Patented Sept. 2, 1930 UNITED srarss PATENT OFFICE .AEROPLANE CONTROL Application filed July 11, 1929, Serial No. 377,449, and n Switzerland August 29, 1928i.

The present invention relates to aeroplane controls and, more especially, to those of the type suitable for use in instructing new pilots.

The system of double j oy-stick control now 5 in common use in aviation schools are generally arranged so as to permit the teacher to throw out of action the joy-stick being manipulated by the pupil and to substitute his own when the occasion appears desirable or necessary. But in double joy-controls of this kind, it has hitherto been impossible during fiight to again reverse control so as to permit the pupil to regain control of his joystick, a landing operation being first required to make the necessary readjustments.

@ne ofthe objects of the present invention is to provide a system of dual joy-stick control permitting one of two pilots to repeatedly throw either one of two joy-sticks into or out of action during flight.

Other objects will appear in the course of the detailed description new to be given with reference to the acompanying drawings, in which Fig. 1 is an elevation, partially in section of one illustrative embodiment of the invention;

Fig. 2 is a plan, partially in section of the structure represented in Fig. 1;

Fig. 3 is a side elevation of tl e same device;

Figs. 4 and 5 are sections taken at right angles to one another of a second form of the invention; y

Fig. 6 represents a third constructive modilication; and

Fig. 7 illustrates a fourth possible embed'- ment of the invention.

Referring to Figs. 1 to 3 of the drawings, there is shown a joy-stick assembly composed i? of a tube 1 pivotally mounted at 3 on a forked element 2, journalled at 4 in fixed supporte,

element 2 controlling the displ cement of the altitude rudder,-a rubber or equivalent,

Llexible tube 6 attac red atopposite extremities by collars 8 and 9 to tube 1 and to a rigid handle 7, having a recess 10 formed therein,

a tube 12 terminatingT in a tapered portion 11,

adapted to slide inside tubes 1 and 6,-and a pair of cables 13, 14 extending to the teacheri' pilots position, cable 18 passing over pulley 17 and terminating at 15 near the upper p art of tube 12, and cable 14 passing over pulley 18, mounted on shaft 19, and terminating at 16 near the bottom of tube 12.

The operation of the device is very simple. Assuming that the student pilot manipulating handle 7 commits some error, the teacherpilot pulls on cable 18 so as displace tube 12 downward thus breaking the rigid connection between elements 7 and l (position shown in Figs. 1 and 3). As soon as the teacher pilot deems it desirable to pass control back to the student, he pulls on cable 14, tube 12 moves upward and rigidifies flexible tube 6 by the interengagement of elements 10 and 1l, and the student may thenceforth reassume full control. Flexible element 6 thus-functions to break operative connection between elements 1 and 7 and permits the teacher to suspend the piloting function of the pupil at will. i

In the modification shown in Figs. 4 `and 5, 'thesrigid connection between the control handle and the pivotally mounted tube is brokenby raising (instead of lowering, as

in Figs. 1 to 3) a central rigidifying tube. Here, the elements corresponding to those shown in Figs. 1 to 3 bear the same numerals and are primed. Tube llterminates at its upperextremity in a flared portion and is adapted to receiverapair of tubes 24 and 26, articulating universally at 25. Manipulating handle 21, 22 is connected to tube 11 by means of a rubber tube 23. When cable 14 is pulled in the direction of arrow 27, tubes 24 and 26 slide upward until universal joint 25 Alies inside flexible portion 23. The pupilpilot is then no longer able to control tube 11. vVhen tractionv is exerted on cable 131 J so asto lower tubes'24, 26 to the position shown in Figs. 4 and 5, rigid connection is reestablished between elements lland 21 and the pupil isA again able to control his joystick. y'

Inthe modification shownin Fig. 6, a handle 28, traverses tube llt similar to tube lof Figs., 1 to 3, and the students control of the joy-stick is suspended by merely drawing handle 28 down into tube 11? by any convenient type of lever, or cable, or hydraulic control.

In the variant represented in Fig. 7, the general assembly is similar to the one shown in Figs. 1 and 3, except that elements 6, 7 and 12 controlling the rigidity of the joystick, are replaced by an assembly composed of tube 1111 (similar to tube 1 of Fig. 1),- a plurality of inter-fitting elements 29,-a handle 30,-and a cable 31. It will be readily seen that when traction is exerted on cable 31 by any convenient form of device, cable 31 acts on handle 30 to bring elements 29 into forced engagement with one another and with tube 1111 so as to render the connection between elements 30 and 1111 substantially rigid. IVhen, on the contrary, cable 31 is slackened, elements 29 no longer maintain the rigidity of the joy-stick, and pressure on handle 30 will not be transmitted to tube 1111.

Various structures are new in use for repeatedly suspending the control of the dircction rudder being manipulated by a student-pilot during flight, this being relatively easy because of the comparatively infrequent modifications in the direction of the plane in the course of a flight. On the contrary, the joy-stick, controlling the altitude rudder, is almost constantly in action and the solution of the problem of throwing a first joy-stick into, and out of action during flight in synchronism with a second joy-stick, presents real difficulties. These latter, it is believed, are overcome by the various forms of the invention hereinabove described.

That is claimed to be novel is l 1. In a joy-stick assembly, a rigid pivotally mounted lever, a rigid handle, a deformable element interposed between said lever and said handle and adapted to be rendered rigid, and means operative to render said deformable element rigid.

2. In a joy-stick assembly, a pivotally mounted tube, a handle, a hollow, flexible tube connecting said tube and handle, a rigid element slidably mounted inside said pivotally mounted and flexible tubes and adapted to engage with said handle, and means for slidably displacing said rigid element inside said tubes whereby said rigid element may establish a rigid connection between the pivotally mounted tube and the handle.

3. In a joy-stick assembly, a pivotally mounted tube, a hollow handle, a rubber tube connecting said tube and handle, a pivotally connected assembly mounted to slide in said pivotally mounted tube and including a rigid element adapted to slide in said rubber Vtube and to form a rigid connection between said pivotally mounted tube and hollow handle. and a tube pivotally connected to said rigid element, and means for moving said last named tube to displace said pivotally connected assembly in either direction.

4C. In a joystick assembly, a rigid pivotally mounted lever, a handle, a flexible tube connecting the lever and the handle, and rigid means adapted to be passed through said tube to render the joy stick rigid.

5l In a joy-stick assembly, a pivotally mounted stick having a flexible portion intermediate the ends thereof, a second stick slidably mounted within said first stick and having a pivotal joint intermediate the ends thereof, and means for causing relative movement of said sticks so as to render the first stick rigid or non-rigid at will.

In testimony whereof I have signed this specification.

OTTO ADOLPHE SCHAER. 

